Monday, September 28, 2009

Came across this paper on a wearable system that employs a small eye tracker and a head mounted display for augmented reality. I've previously posted a video on the same system. It's a future technology with great potential, only imagination sets the limit here. There is a lot of progress in image/object recognition and location awareness taking place right now (with all the associated non-trivial problems to solve!)

Abstract"Undisturbed interaction is essential to provide immersive AR environments. There have been a lot of approaches to interact with VEs (virtual environments) so far, especially in hand metaphor. When the user‟s hands are being used for hand-based work such as maintenance and repair, necessity of alternative interaction technique has arisen. In recent research, hands-free gaze information is adopted to AR to perform original actions in concurrence with interaction. [3, 4]. There has been little progress on that research, still at a pilot study in a laboratory setting. In this paper, we introduce such a simple WARS(wearable augmented reality system) equipped with an HMD, scene camera, eye tracker. We propose „Aging‟ technique improving traditional dwell-time selection, demonstrate AR gallery – dynamic exhibition space with wearable system."

Friday, September 18, 2009

For some time I've been following the EyeWriter project which aims at enabling Tony, who has ALS, to draw graffiti using eye gaze alone. The open source eye tracker is available at Google code and is based on C++, OpenFrameworks and OpenCV. The current version supports basic pupil tracking based on image thresholding and blob detection but they are aiming for remote tracking using IR glints. Keep up the great work guys!

Monday, September 14, 2009

From the Helsinki Institute for Information Technology, Finland, comes a research prototype called GaZIR for gaze based image retrieval built by Laszlo Kozma, Arto Klami and Samuel Kaski. The GaZIR prototype uses a light-weight logistic regression model as a mechanism for predicting relevance based on eye movement data (such as viewing time, revisit counts, fixation length etc.) All occurring on-line in real time. The system is build around the PicSOM (paper) retrieval engine which is based on tree structured self-organizing maps (TS-SOMs). When provided a set of reference images the PicSOM engine goes online to download a set of similar images (based on color, texture or shape)

Abstract"We introduce GaZIR, a gaze-based interface for browsing and searching for images. The system computes on-line predictions of relevance of images based on implicit feedback, and when the user zooms in, the images predicted to be the most relevant are brought out. The key novelty is that the relevance feedback is inferred from implicit cues obtained in real-time from the gaze pattern, using an estimator learned during a separate training phase. The natural zooming interface can be connected to any content-based information retrieval engine operating on user feedback. We show with experiments on one engine that there is sufficient amount of information in the gaze patterns to make the estimated relevance feedback a viable choice to complement or even replace explicit feedback by pointing-and-clicking."

Fig1. "Screenshot of the GaZIR interface. Relevance feedback gathered from outer rings influences the images retrieved for the inner rings, and the user can zoom in to reveal more rings."

Fig2. "Precision-recall and ROC curves for userindependent relevance prediction model. The predictions (solid line) are clearly above the baseline of random ranking (dash-dotted line), showing that relevance of images can be predicted from eye movements. The retrieval accuracy is also above the baseline provided by a naive model making a binary relevance judgement based on whether the image was viewed or not (dashed line), demonstrating the gain from more advanced gaze modeling."

Fig 3. "Retrieval performance in real user experiments. The bars indicate the proportion of relevant images shown during the search in six different search tasks for three different feedback methods. Explicit denotes the standard point-and-click feedback, predicted means implicit feedback inferred from gaze, and random is the baseline of providing random feedback. In all cases both actual feedback types outperform the baseline, but the relative performance of explicit and implicit feedback depends on the search task."

Friday, September 11, 2009

From Markus Nyström and Kenneth Holmqvist at the Lund UniversityHumanities Lab (HumLab) in Sweden comes an interesting paper on a novel algorithm that is capable of detecting glissades (aka dynamic overshoot) in eye tracker data. These are wobbling eye movements often found at the end of saccades and has previously been considered errors in saccadic programming with limited value. What ever their function is the phenomena does exists and should be accounted for. The paper reports finding glissades following half of all saccades while reading or viewing scenes, and has an average duration of 24 ms. This is work is important as it extends the default categorization of eye movement e.g. fixation, saccade, smooth pursuit, and blink. The algorithm is based on velocity saccade detection and is driven by data while containing a limited number of subjective settings. The algorithm contains a number of improvements such as thresholds for peak- and saccade onset/offset detection, adaptive threshold adjustment based on local noise levels, physical constraints on eye-movements to exclude noise and jitter, and new recommendations for minimum allowed fixation and saccade duration. Also, important to note that the data was obtained using a high-speed 1250 Hz SMI system, how the algorithm performs on a typical remote tracker running at 50-250Hz has yet to be defined.

Wednesday, September 9, 2009

"PsychNology Journal (ISSN 1720-7525) is a quadrimestral, international, peer-reviewed journal on the relationship between humans and technology. The name 'PsychNology' emphasizes its multidisciplinary interest in all issues related to the human adoption and development of technologies. Its broad scope allows to host in a sole venue advances and ideas that would otherwise remain confined within separate communities or disciplines. PNJ is an independent, electronic publication that leaves the copyright to authors, and provides wide accessibility to their papers through the Internet and several indexing and abstracting services including PsycInfo and EBSCO."

The Psychnology Journal Special edition on Gaze control for work and play is now available online. It contains some of the highlights from the Cogain conference last year in an extended journal format. For the COGAIN people this is old news, for the rest it's hopefully interesting stuff. The NeoVisus prototype I presented in Prague should have appeared but unfortunately did not have the time to make the necessary changes. More information on the scrollable keyboard and text entry by gaze in general is available in Päivi's excellent Ph.D thesis. Also, rumor has it that Javier San Agustin's Ph.D thesis gaze interaction and a low-cost alternative is getting closer to D-day. We're all looking forward to it, hang in there mate =)